Hi - My husband has a dark ring around both knee caps - the center is grayish in color and feels as tho there may be some fluid. He has pain on and off. When his leg is straight, the knee cap looks sunken. He as worked many years as a high line electrician, in and out of the bucket truck daily, long hours on his feet and/or knees. He has had this for several months and only recently put in a request to see a dr. He is incarcerated and it may take some time to see a dr, get any test, diagnosis, and treatment. He is taking pain meds daily - either Advil or Motrin. He has recently began teaching a class for electrical trade and no longer in the bucket truck, but is on his feet and walks a lot around the compound. PLEASE advise me as to any suggestions! I am unable to get a photo due to his incarceration. We sincerely appreciate your help! Shelia